net/lftp: update to 4.7.4

Update lftp to upstream release 4.7.4
Also update the list of package mirrors.

Signed-off-by: Paul Wassi <p.wassi@gmx.at>

net/lftp/Makefile

@@ -8,14 +8,12 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=lftp
-PKG_VERSION:=4.7.3
+PKG_VERSION:=4.7.4
 PKG_RELEASE:=1
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
-PKG_SOURCE_URL:=http://lftp.yar.ru/ftp \
-		http://lftp.yar.ru/ftp/old \
-		http://lftp.cybermirror.org \
-		http://lftp.cybermirror.org/old
-PKG_MD5SUM:=23deda16014412c802f095fbaa0bebee
+PKG_SOURCE_URL:=http://lftp.tech/ftp/ \
+		ftp://ftp.st.ryukoku.ac.jp/pub/network/ftp/lftp/
+PKG_MD5SUM:=74965c798b1806d0a2659d8a606ea47f